Currently, in-flight communications services for commercial and private aircraft are provided by geostationary earth orbit satellites and/or ground to air terminals. Such in-flight systems, while effective, have a number of disadvantages. For instance, communication coverage from satellites requires that aircraft include large aperture steerable antennas mounted on the aircraft fuselage. These antennas may be mechanically-steered, in which case they must be contained within radomes for protection from the elements. However, radomes create air drag on the airplane, which increases fuel consumption. The antennas may alternatively be electronically steered, in which case they may have limited scan angles that limits their deployment to low latitudes and limit their longitudinal coverage. Also, in order to have as low a profile as possible, the antennas are configured to have a broader beam in one dimension with increased sidelobe levels. These higher sidelobes create potential interference with adjacent satellites on the geostationary arc requiring more frequent handovers. Additionally, the capacity of such systems operating typically in the Ku and Ka bands is low because of the available spectrum and competition with satellite-to-ground coverage.
Communications services to aircraft may also be provided by ground-based gateway stations that communicate directly with the aircraft. This ground-to-air service is limited by available spectrum typically at the S-band. Known ground-to-air service has a limited throughput of about 3 Mbps per aircraft. Also, known ground-to-air links are susceptible to rain and scintillation fading at low elevation angles because the signal goes through the low atmosphere.